Control of electromagnetic actuators particularly for operating print hammers is of crucial importance. In using the energization of a coil to effect a work action such as printing, it is highly desirable to be able to apply the same total amount of energy to the coil every time it is energized. This guarantees that the hammer will impact the print medium with a constant force. It is also desirable or necessary in some print hammer control systems to operate the hammer driver each time for the same interval of time. It is further desirable that the energy level can be easily adjusted to take into account different forms thicknesses used in printing. A number of techniques have been used in the prior art to achieve precision hammer control.